The invention relates to a hardware device for the adjustable fastening of a drawer front to its sides, with a fastening member attachable to the drawer front and a mounting member which can be releasably joined to the fastening member and is provided on the corresponding drawer side, the fastening part of which has a fastening lug with flat sides running parallel to the drawer side and projecting substantially at a right angle from the inside surface of the drawer front, in which a slot running perpendicularly and substantially parallel to the inside surface and open at the bottom end is provided, and the mounting member has a mounting stud projecting from the outside surface of the drawer side and having a diameter slightly smaller than the width of the slot measured horizontally, and whose height projecting beyond the outside surface of the drawer side is slightly smaller than the thickness of the fastening lug, a threaded bore being provided in the front end of the mounting stud, into which the shaft of a fastening screw is driven, which can be driven into the stud with a washer disposed on its head into gripping contact of its head with the outside surface of the fastening lug.
Drawers today are mostly provided on their visible front with drawer fronts which overlap the actual drawer box in height and width and which therefore, when in the position fully withdrawn into the corresponding cabinet carcase, lie snugly, like lipped doors, against the carcase; in the case of the top and bottom drawers of a chest of drawers, their projecting top and bottom margins lie against the edges of the carcase. The problem then arises that the drawer fronts have to be aligned with the drawer fronts of laterally or vertically adjacent drawers and/or the cabinet side walls such that, in the closed state, they will have an aesthetically pleasing exact alignment. Whenever false facings were placed on the actual drawer fronts and screwed thereon, such alignment was relatively easy to achieve by making the hole for the screws driven from the inside of the drawer through the drawer front into the drawer facing larger than the shaft of the screws, so that the facing could be shifted by loosening the screws and moving it within the space allowed by the oversized holes. By tightening the screws after completing the alignment, the facings were then affixed to the drawer front. In recent times drawers are increasingly being made without a false facing, i.e., the facings simultaneously constitute the drawer front and therefore they have to be able to be affixed to the drawer box in order to stabilize the drawer at its forward area. On the other hand, however, the described alignment must nevertheless be possible. Mounting hardware of various kinds have been developed for this purpose, some of which additionally serve to mount the front end of the rail of the drawer slide holding the drawer on the cabinet carcase (DE-OS 36 32 442). This mounting hardware is disposed on the inside surface of the drawer side under the drawer bottom. But then, to enable the drawer front to be fastened tightly to the drawer sides--at least in the case of drawers of great vertical depth--additional fastening means in the nature of corner fasteners must be provided above the bottom level, which likewise must permit adjustment of the drawer front and also must be inconspicuous. In recent times, in the case of drawers with hollow sides made of plastic or metal and used for certain applications, mounting hardware disposed inside of the hollow drawer sides has been used for drawer fronts (e.g., EP-OS 0 267 477), in which a mounting member is fastened to the drawer front, which can be hung on a leaf spring which in turn is disposed for adjustment in the vertical and closing direction of the drawer in a supporting member disposed in the interior of the hollow drawer side. For the transverse adjustment of the drawer front, the mounting member itself is again so subdivided that these members are transversely adjustable relative to one another. This known hardware is of relatively complex configuration and is accordingly difficult and expensive to manufacture.
In addition to drawers with sides made from the above-mentioned hollow shapes--for reasons of cost, among others--those made of single-wall extruded aluminum shapes or of sheet metal shapes are also used in the manufacture of drawers in which a concealed arrangement of the drawer front mounting hardware is not possible.
Mounting hardware of the above-mentioned kind has been developed for these applications (DE-OS 40 26 407), the dimensions of which are comparatively small, and it permits the adjustment of the drawer front relative to the drawer sides horizontally and, if necessary, vertically also. For the drawer front, after initial assembly or an adjustment operation, to be drawn tightly against the front edges of the drawer sides and bottom by tightening the screw, the side of the slot in the lug that is remote from the drawer front is provided with a ramp on which the washer provided under the head of the screw is placed. When the screw is tightened after another adjustment, therefore, the wedge effect of this ramp draws the lug and thus the drawer front against the corresponding drawer side. The tightening force is thus produced on the side of the lug remote from the drawer front and through the relatively slender top of the lug where it bridges the end of the slot. Thus a bending moment is produced in this upper part of the lug, which seeks to widen the slot. In an extreme case the lug can even break where it spans the slot, in the case of previous damage or excessive tightening.
The invention, accordingly, is addressed to the problem of proposing a fastening means for the fronts of drawers, which will enable drawer fronts to be fastened tightly, but adjustably in the necessary coordinate directions, either to single-wall drawer sides of metal or to wooden drawer sides, and will provide greater strength than the known hardware without being of greater size or complexity. Furthermore, the setting of the level of the drawer front relative to the drawer sides or bottom of the drawer is to be secured not only by the clamping action of the mounting screw but also by the interlocking of the hardware members with one another.
Setting out from hardware of the kind described above, this problem is solved in accordance with the invention by providing the mounting lug in its area between the slot and the drawer front, with a groove running parallel to the slot and having a ramp surface running parallel to the seat and sloping--seen in a plane parallel to the drawer bottom away from the drawer front and from the corresponding drawer-side, on which an elongate margin of the washer, bent at a complementary angle, is supported. The force drawing the drawer front against the corresponding drawer side is thus produced in the area located between the slot and the drawer front by the wedging action produced by tightening the screw between the ramp and the elongate margin of the washer, so that the cross section of the lug's bridge portion spanning the upper end of the slot is completely relieved of stress.
To enable the said wedging action between the ramp of the groove in the lug to be produced in the mounting lug and in the bent margin of the washer, the horizontal distance `A`, measured from the longitudinal central plane of the slot in the mounting lug to the upper edge of the ramp sloping away from the bottom of the groove, is slightly greater than the distance `a` measured from the central axis of the screw hole in the washer to its bent elongate margin, this distance `a` being measured on the bottom of the washer facing the mounting lug.
To secure the setting of the level of the drawer front, there is provided, in further development of the invention, in the area of the lug spanning the upper end of the slot, a threaded bore passing from the top boundary surface all the way into the slot, in which the shaft of a level adjusting screw provided with a complementary thread is engaged with its extremity pointing toward the slot and thrusting against the stud of the mounting part. By rotating the level setting screw clockwise or counterclockwise the free end of the shaft of the mounting screw is driven in or out of the slot and then forms an abutment for the mounting stud. Accidental dropping of the drawer front when the mounting screw is loosened is therefore impossible.
To secure the bent margin of the washer in correct alignment with the ramp in the groove in the lug when the drawer front is installed on the drawer side, i.e., when the mounting stud is inserted into the slot in the mounting lug, it is desirable that the washer be nonrotatable with respect to its alignment with the mounting stud, and instead that it be held displaceably in the direction of its longitudinal central axis on the mounting member and drawer side.
The washer preferably has a square or rectangular shape with the elongate, bent margin on one side, and then on the side of the washer adjoining it at right angles and facing the bottom, open end of the slot when it is in the proper mounting position, a tongue is provided projecting toward the drawer side, which can be displaced lengthwise in an opening or groove in the drawer side or in the mounting stud.
Preferably, the tongue engages a longitudinal groove made in the circumferential surface of the mounting stud.
To be able to install the lug on the mounting stud even if the mounting screw is only slightly loosened, an embodiment is recommended in which the groove is open at its bottom end in the bottom boundary surface of the lug.
The mounting lug is best provided, as in the known hardware, on a mounting flange in which at least one hole is provided for each screw that can be driven into the drawer front, these holes being best in the form of horizontal slots, thereby permitting a transverse adjustment of the drawer front within the range permitted by the slots.
The most rigid and strong fastening of the stud to the drawer side is preferably achieved if a hole complementary to the stud is made through the drawer side, in which case a flange of greater diameter is then provided on the drawer-side end of the stud. When the stud is in the proper position for fastening to the drawer side, this flange will then lie against the inside surface of the corresponding drawer side and secure the stud against withdrawal from the corresponding hole in the drawer side. The securing of the stud in the opposite direction, i.e., against any forcing of the stud toward the drawer interior, can be accomplished either by an appropriately tight fit of the stud in the associated hole in the drawer side, or, in the case of drawer sides made from sheet metal, by any additional method, such as welding, soldering or even peening.
After the drawer front has been fastened to the drawer box in the correct position, a cover can be placed onto the hardware assembly. This cover can be made of thin plastic and made so as to be snapped onto it, since it has no need to withstand any fastening forces.